Larval ecology of a suite of snappers (family: Lutjanidae) in the Straits of Florida, western Atlantic Ocean

Abstract

Despite the ecological and economic importance of western Atlantic Ocean lutjanid spe- cies, little is known about their larval stage. Pelagic larval distribution, abundance, growth, mortality, and spawning patterns of 6 western Atlantic snapper species were examined from ichthyoplankton samples collected monthly over 2 yr along a transect spanning the east-west axis of the Straits of Florida (SOF). Successful spawning occurred primarily from July to September when water temper- atures were warmest and larvae were most abundant in the upper 50 m towards the east or west sides of the SOF. Species-specific variability in spatiotemporal larval patterns tracked adult life history characters. Larvae of species associated with shallow coral reefs were spawned in the waning half of the lunar cycle (third quarter to new moon), were most abundant in the 0 to 25 m depth range, and where cross-SOF distributions were not uniform, were distributed mainly towards the eastern SOF. Larvae of deeper-dwelling species exhibited lower mortality and no lunar pattern in spawning (Etelis oculatus only), were distributed deeper in the water column and occurred progressively deeper with ontogeny, and where cross-SOF distributions were not uniform, were most abundant in the western SOF. Despite species-specific variability in spatial distributions and equivalent east-west mortality rates, at least one measure of larval growth in 4 of 6 species of snapper revealed significantly faster growth in the western versus the eastern SOF, which may be related to higher prey availability in the west. Results of this study provide insight into the pelagic phase of 6 important snapper species, with implications for understanding adult populations.